1. Technical Field
The present invention relates generally to video signal analysis, and more particularly, to methods and systems for analyzing and transmitting video signal parameters from arbitrary signal sources of imaging modalities including medical devices.
2. Related Art
As a general matter, the display of video on conventional display devices involves electrical signals that sweep or scan across the field of the screen one line at a time, with the amplitude at a given point in time being representative of the instantaneous brightness at corresponding location on the screen. The picture may be interlaced, where each frame is divided into two fields that are each scanned separately, or progressive, where all of the horizontal lines in the field are scanned in a single pass. There are a number of ways to structure the signal to provide different display characteristics such as resolution, frame rate, aspect ratio, color space, and the like. The signal is segregated into multiple parts, with each part corresponding to a different type of display information. These signaling systems were originally developed for analog cathode ray tube (CRT) devices, though the principles are equally applicable to more modern technologies such as liquid crystal displays (LCDs), plasma display panels, light emitting diode (LED) displays, organic light emitting diode (OLED) displays, and so forth.
In order to properly display the video, it is necessary for the display device to be coordinated with the device generating the video signal. Certain key parameters must be matched between the generating device and the display device. Because broadcast television sets are manufactured by a wide variety of companies different from those manufacturing the signal generators, a number of standards have been developed and promulgated to ensure compatibility. For example, television sets used in the United States, Japan, and a few other countries conform to the National Television System Committee (NTSC) standard, while European countries and certain others conform to the Phase Altering Line (PAL) standard. Additionally, computer display devices similarly have various standards such as Video Graphics Array (VGA), eXtended Graphics Array (XGA), and the like.
Electronic displays are frequently utilized in medical imaging/diagnostic systems. There are various such imaging modalities, including Computed Tomography (CT), Magnetic Resonance Imaging (MRI), catheterization imaging, Computed Radiography (CR), Positron Emission Tomography (PET) and other nuclear medicine diagnostic systems, and ultrasound. Because the display devices were typically developed in conjunction with the imaging modalities, it was unnecessary to develop display standards as with broadcast video and computer systems. Accordingly, there are a vast number of presently deployed imaging modalities that have different, undocumented video signal parameters. Furthermore, there is no known compilation of all of the video signal parameters for all of existing imaging modalities.
When the display devices connected to these imaging modalities malfunction, it is often difficult to select a suitable replacement device because of the unknown video signal parameters. Furthermore, as more advanced display devices become more widely available relative to the older CRT devices, there has been an industry trend to replace such legacy components with newer alternatives such as, for example, LCD displays. But again, because of the lack of complete and accurate information for the video signal parameters of the imaging modalities, a component upgrade program has been difficult to manage. Conventionally, the output signal from the imaging modality must be analyzed with an oscilloscope in a time-consuming process, which requires a qualified on-site technician. In the alternative, the legacy display device may be sent to a maintenance center, whereupon it is examined to ascertain the unknown video signal parameters in a lengthy trial-and-error procedure. With the aforementioned upgrade programs, a video scaler may be programmed and attached to the imaging modality to drive the new LCD display, but the need to ascertain the appropriate video signal parameters still remains. Accordingly, there is a need in the art for an improved method and system for video parameter analysis and transmission.